Characterization of novel structures of mannosylinositolphosphorylceramides from the yeast forms of Sporothrix schenckii

Novel structures of glycoinositolphosphorylceramide (GIPC) from the infecti ve yeast form of Sporothrix schenckii were determined by methylation analys is, mass spectrometry and NMR spectroscopy. The lipid portion was character ized as a ceramide composed of C-18 phytosphingosine N-acylated by either 2 -hydroxylignoceric acid (80%), lignoceric (15%) or 2,3-dihydroxylignoceric acids (5%). The ceramide was linked through a phosphodiester to myo-inosito l (Ins) which is substituted on position O-6 by an oligomannose chain. GIPC -derived Ins oligomannosides were liberated by ammonolysis and characterize d as: Manp alpha1-->6Ins Manp alpha1-->3Manp alpha1-6Ins Manp alpha1-->6Manp alpha1-->3Manp alpha1-->3Manp alpha1-->6Ins Manp alpha1-->2Manp alpha1-->6Manp alpha1-->3Manp alpha1-->3Manp alpha1-->6 Ins These structures comprise a novel family of fungal GIPC, as they contain th e Manp alpha1-->6Ins substructure, which has not previously been characteri zed unambigously, and may be acylated with a 2,3 dihydroxylignoceric fatty acid, a feature hitherto undescribed in fungal lipids.